The present invention relates generally to the transmission of wireless infrared (IR) signals, and, more particularly, to a system and method for using IR packet delivery in a wireless keyboard having a pointing device.
The use of wireless IR communications has been known for quite some time. A typical application for such IR communications has been, and is currently, for remote control of electronic devices. For example, the remote control that is used with most television sets, video cassette recorders (VCR""s), home audio systems, etc., makes use of IR technology to communicate commands from the remote control device to the electronic equipment. Such commands may be used to control whether the device is on or off, to control the volume, to control the channel to which the device is tuned, etc. Typically, the remote control includes circuitry that detects the actuation of one of the control keys, or buttons. Each control key on the remote control has a digital code associated therewith. When a particular key is pressed the logic within the remote control determines the code associated with the pressed key, modulates an IR radio frequency (RF) carrier with that code, and transmits the IR signal including the code associated with the pressed key to a receiver located at the electronic device.
In some applications the IR receiver may be located within the electronic device, and in other applications the IR receiver may reside in a separate control box. For example, the receiver may be located within a settop control box associated with a television set.
A new application for IR remote control functions is a wireless typewriter style keyboard. Such a wireless keyboard would be useful in applications in which it is desirable to use a television set for more than merely viewing television programming. For example, new broadband services make available to customers the ability to interact with a television set. Such services may include the use of a television and a special settop box that enables a user to connect to the Internet using the special settop box. In such an arrangement, the television is used as the monitor over which a user views Internet web sites. In such an application, it would be desirable to have a wireless typewriter style keyboard that the user can use to communicate with the special settop box in order to navigate or surf the Internet. Such a wireless typewriter style keyboard can make use of IR communication technology to communicate commands to the special settop box.
Most typewriter style keyboards adhere to what is known as the International Business Machines (IBM(copyright)) standard keyboard, hereinafter referred to as a standard, or conventional keyboard. The standard keyboard includes certain features that have become industry standard. For example, a standard keyboard defines certain keys as xe2x80x9ctypematicxe2x80x9d keys. Typematic keys are keys that will repeat if continually held down. For example, were a user of a personal computer running a word processing program to hold down the xe2x80x9caxe2x80x9d key on a standard keyboard, the letter xe2x80x9caxe2x80x9d will be duplicated on the screen for as long as the xe2x80x9caxe2x80x9d key is held down.
In a wireless IR keyboard as described above, and similar to the wireless IR remote control described above, each time a keyboard key is pressed a digital code corresponding to the pressed key is generated, modulated onto an RF IR carrier, and transmitted to the special settop box. The settop box receives the RF IR signal, decodes the signal and determines which key was pressed.
One of the difficulties in such a wireless IR keyboard is related to correctly interpreting the code corresponding to the pressed key. Of particular concern is determining whether a key is being held down or whether a different key is pressed. In order to compensate for this, most IR communication protocols include a minimum timing delay between transmissions of IR packets. For example, a minimum time delay can be inserted between code transmissions such that accurate determination may be made if a key is being held down. In such systems, the timing of the standard functions (such as the typematic keys described above) may not always coincide with the standard IR protocol timing requirements.
Therefore, it would be desirable to devise an IR communication protocol that can seamlessly integrate standard keyboard functionality into an existing IR communication protocol.
The invention provides a keyboard and method for transmitting IR signals corresponding to key presses and releases on an IR keyboard.
In architecture, the invention may be conceptualized as an IR keyboard having a communication protocol comprising circuitry configured to convert a standard recognized keystroke into a corresponding IR data word and circuitry configured to transmit the IR data word.
The present invention may also be conceptualized as a method for operating an infrared (IR) keyboard, the method comprising the steps of detecting, in a keyboard, a standard recognized keystroke, converting the standard recognized keystroke into a corresponding IR data word, and transmitting the IR data word.